Page 151 Speed Level Series - Service & Parts Manual
January 2019Section 9 - Troubleshooting - 3084ES Models
No drive elevated
Unit out of level Lower and re-position the machine.
Batteries discharged
Will receive 4-4 or 7-7 flash on GP400. Clean, service
and charge batteries.
Battery charger may not operate if battery voltage
drops below 20 volts
Slow drive with
platform in
stowed position
System interlock Check HELP messages using EZ-Cal
High torque enabled Check Speed/Torque Switch at platform controls
Elevation sensor out of calibration
Use EZ-Cal to monitor platform state of elevation. See
Diagnostic chart I.D. 2a13 for elevated status and 2e1
for platform % of elevation input. Failure of the angle
transducer will trigger a fault code.
Malfunctioning rear wheel bypass
valve
Located on rear wheel motors only. Check by
replacing valves.
Wheel motor/s not functioning
correctly
Inspect wheel motors for excessive bypass
Poor gradability
performance
High or Mid Speed enabled Check Speed/Torque Switch
Batteries discharged
Will receive 4-4 or 7-7 flash on GP400, Clean, service
and charge batteries.
Battery charger may not operate if battery voltage
drops below 20 volts
Wheel motor/s not functioning
correctly
Inspect wheel motors for excessive bypass
Malfunctioning Rear wheel bypass
valve
Located on rear wheel motors only. Check electrical
by disconnecting valves or function by replacing
valves
Malfunctioning Series/Parallel Valves Located on top of main hydraulic Manifold
Worn hydraulic pump Check with flow meter or replace pump
Drive in one
direction only
Drive Valve SVD1 not energizing in
one direction
Check 12 volts to appropriate coil, check coil, check
valve function
Counterbalance Valve CBV1 or
CBV2 malfunction
Swap counterbalance valves to see if functioning
direction changes.
No output from GP400
Scan using EZ-Cal and troubleshooting charts. EZ-Cal
chart I.D 4f-7 - Fwd or 2f-9 - Reverse
No Low Speed
(high torque
mode)
Speed/torque selector switch
inoperative
Check continuity of Speed/Torque switch in platform
control box
Valve SV3 not functioning
Check for 12 volts and ground to valve check for faulty
valve spool
EP1 poppet valve not functioning Check or replace valve
No Mid Speed
SV3 or SV4 powered and/or shifted
These valves should not have 12 volts, in mid-speed,
check valve function
Speed/torque selector switch
malfunction
Check continuity through switch
No High Speed
Speed/torque selector switch
inoperative
Check continuity of Speed/Torque switch in platform
control box
Valve SV4 not functioning
Check voltage and ground to valve check for faulty
valve spool
EP2 poppet valve not functioning Check or replace valve
No brake
effectiveness
Brake Orifice OD-1 obstructed
Remove, clean orifice. See hydraulic diagram for
location in manifold.
Brake discs worn past service limit Replace brake discs located inside rear wheel motors.
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